Method and device for removing a foil wrapping drawn over a stack of goods

ABSTRACT

A process is disclosed for removing a shrink wrapping drawn over a stack of goods. The shrink wrapping is vertically cut at one side of the stack of goods, one edge of the cut is held and secured to a winding spindle, and the winding spindle is then guided around the stack of goods so that the shrink wrapping is winded on the winding spindle that rotates around its longitudinal axis. Also disclosed is a device for carrying out the process.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a national phase of PCT/EP94/03185 filed 23 Sep.1994 and based, in turn, upon German National Application P 44 00 661.6of 12 Jan. 1994 and G 93 14 339.7 of 23 Sep. 1993 under theInternational Convention.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a national phase of PCT/EP94/03185 filed 23 Sep.1994 and based, in turn, upon German National Application P 44 00 661.6of 12 Jan. 1994 and G 93 14 339.7 of 23 Sep. 1993 under theInternational Convention.

FIELD OF THE INVENTION

The invention relates to a method of removing a foil wrapping drawn overa stack of goods. The invention also relates to a device for carryingout the method.

1. Background of the Invention

In practice, stacks of goods, especially palletted goods, are securedwith shrink foil or stretch foil, transported and delivered to the user.The user has to remove the foil in order to unpack the stack of goods.Usually this has been is done by hand.

2. Object of the Invention

It is the object of the invention to mechanize the removal of the foil.

SUMMARY OF THE INVENTION

This object is achieved with a method for the removal of a wrappingdrawn over a stack of goods by vertically cutting the foil wrapping onone side of the stack of goods, by seizing one edge of the cut andfastening it to the winding spindle and guiding, the winding spindlearound the stack of goods, thereby wrapping the foil around the windingspindle rotating about its longitudinal axis. In order to avoid damageto the stack of goods or to the goods stacked therein, the foil wrappingcan be lifted off the stack of goods, area by area, and then cut open.The foil wrapped around the winding spindle is removed from the windingspindle and can then be disposed of, or first compacted and thendisposed of.

It is suitable to guide the winding spindle around the stack of goods bykeeping a constant distance therefrom, because then the forces acting onthe foil remain basically constant and the tearing lines in the foilcontinue in the peripheral direction of the stack of goods. Particularlythe winding spindle rotating about its longitudinal axis can pull itselfaround the stack of goods without additional actuation at the foil.

When the tearing of the foil is desired in a certain area, e.g. so thatthe upper part of the stack of goods still remains covered by a partialfoil wrapping, the foil wrapping is heated below the upper part of thestack of goods. The same applies when the desired tearing line is in thearea of a support (pallet) of the stack of goods, for which purpose thefoil wrapping is heated in the area of the support (pallet) of the stackof goods.

The stack of goods can be lifted, in order to eliminate possibleshrinkage of the foil wrapping at the bottom.

A device for carrying out the method is equipped with a frame, asupporting arm on the frame and which is pivotable about a vertical axisand can be driven around the axis, for a winding spindle suspendedtherefrom. Such devices are known for wrapping a stack of goods. Incontrast thereto the device of the invention is characterized in that onthe supporting arm a guide slide carriage movable in its longitudinaldirection is arranged, that the winding spindle and a guide mastextending parallel thereto are suspended on the guide slide carriage,and that a vertically displaceable lifting slide carriage with aseparating device is guided on the guide mast. In particular the liftingslide carriage can have a suction device connectable to a suctionsource, by means of which the foil can be lifted off the stack of goods,area by area. The separating device can be a blade movable along thelifting slide carriage by means of a drive, particularly a liftingcylinder, or a heating wire extending parallel to the winding spindle.Further on the guide mast hot air nozzles can be provided, which aredirected so that they heat the portion of the foil in front of thewinding spindle in the direction of rotation, thereby defining thementioned tearing lines. For the transfer of the cutoff edge to thewinding spindle, the winding spindle can be associated, at least incertain areas, with a gripping device, which seizes the free cutoff edgeand clamps it to the winding spindle.

Underneath the frame it is possible to provide a hoisting device for thestack of goods, so that the bottom shrinkage can be removed when thestack of goods is lifted. Finally also holding-down means which can belowered unto the upper side of the stack of goods could be provided,which holds the foil on the upper side of the stack of goods, while thesides of the foil wrapping are removed. The holding-down means could beprovided with heating wires, particularly arranged in a stellar pattern,for producing the desired tearing lines in the upper side of the foil.

BRIEF DESCRIPTION OF THE DRAWING

The above and other objects, features, and advantages will become morereadily apparent from the following description, reference being made tothe accompanying drawing in which:

FIG. 1 is a schematic side view of a device for the removal of a foilwrapping drawn over a stack of goods;

FIG. 2 is a schematic top view of the device of FIG. 1;

FIG. 3 is a view similar to FIG. 2 showing the mechanism in a differentfunctional position;

FIG. 4 is a schematic partial top view of the stack of goods and thegripping device, drawn to an enlarged scale;

FIG. 5 is a view of a portion of the mechanism of FIG. 4 in a differentfunctional position; and

FIG. 6 is a view similar to FIG. 1, but with the foil unwrapped from thestack of goods and with foil compactor.

SPECIFIC DESCRIPTION

By means of the illustrated device the shrink foil wrapping 2 can beremoved from a palletted stack of goods 1 protected by the shrink foilwrapping, which also reaches the underside of the pallet 4 with a bottomshrinkage 3. For this purpose the stack of goods 1 is transported undera frame 5 and positioned on a lifting mechanism 6 (FIG. 1). Aholding-down means 7 provided at its underside with heating wires 27(FIG. 2) arranged in a stellar pattern is lowered onto the upper side ofthe stack of goods.

A turntable 8, rotatable about a vertical axis, is supported on theupper side of frame 5 and is rotatable by a drive 8a. From the turntable8 a supporting arm 9 extends horizontally and has on its underside aguide 10 for a guide slide carriage 11. The guide slide carriage 11 canbe moved back and forth in the longitudinal direction of the supportingarm 9 by a drive 11a.

On the basic frame 5 a horizontal slide 28 with a vertical guide mast 12is suspended, in whose upper area a lifting slide carriage 13 can bemoved up and down by means of a drive 13a, in order to adjust to thepallet height. On its side facing the stack of goods 1 the lifting slidecarriage 13 carries a suction device 14 connected to a suction source14a and which can be swung by lifting cylinders, and also a U-shapedseparating device 15 swingable by lifting cylinders. The same suctiondevice 14 and the separating device 15 are fastened to the lower part ofthe guide mast 12. The mast is provided with hot air nozzles 12' formedalong the mast.

The horizontal slide 28 engages via a spindle 28a driven by a liftingcylinder in the guide slide carriage 11 of the winding spindle 19. Afterthat the horizontal slide 28 with the winding spindle 19, the suctiondevice 14 and the separating device 15 are moved against the stack ofgoods 1, whereby the suction device 14 affixes itself by suction to theshrink foil wrapping 2. Then the suction device 14 is moved towards thewinding spindle 19 by means of a lifting cylinder, and thereby theaspired shrink foil wrapping 2 is pulled towards the U-shaped heatingwire of the separating device 15, whereby a U-shaped foil tab 2a isseparated from the shrink foil wrapping 2. After that the windingspindle 19 with its fixed cheek 19b rotates past the suction device 14and is closed by a lever system 29 fastened to the horizontal slide 28,which with the assistance of lifting cylinders closes the loose cheek19a against the fixed cheek 19b (FIG. 4), whereby the foil tabs 2a arefastened in the winding spindle 19 by clamping. The winding spindle 19is moved a little further from the pallet by the guide slide carriage11, whereby the shrink foil wrapping 2 pulls itself away from the loadbetween the two foil tabs 2a. A vertical heating wire 30 having anantiadhesion coating 30' thereon can be swung against a pulled off foilarea to separate a pulled off portion. After the free cutoff edge ofboth foil tabs 2a is fastened in the winding spindle 19, the windingspindle 19 with the supporting arm 9 travels around the stack ofgoods 1. Thereby the foil is wrapped around the winding spindle 19rotating about its vertical axis. This applies also to the foil of thebottom shrinkage 3.

The foil on the upper side of the stack of goods 1 is separated intosegments by the heating wires 27 of the holding-down means 7, whichduring the winding of the foil are pulled out under the holding-downmeans 7.

The separating device 15 consists basically of a U-shaped frame builtaround the suction device 14 with blades or separating heating wires notshown in the drawing. It separates the foil 2 which is pulled by thesuction device 14 against the separating device 15. The separatingdevice 15 produces a U-shaped tearing line around the suction device 14.

The suction device 14 is removed from the stack of goods 1 and movedinto the recess of the winding spindle 19. Thereby it entrains the freeedge of foil tabs 2a, which have resulted from the U-shaped cut or theU-shaped fusion lines. Then the winding spindle 19 picks up the foiltabs 2a, which have become accessible to be clamped by the windingspindle due to a free space between the suction devices 14.

The winding spindle 19 can change its circumference by retracting itscheek 19a, which extends over the entire length of the winding spindle19.

Thus it becomes possible for the foil tabs 2a to be clamped between thecheeks 19a and 19b after the swing out of the cheek 19a of the windingspindle 19.

This construction also makes possible a simple disposal of the foil 2from the winding spindle 19, by swinging in the cheek 19a, therebycancelling the clamping effect and also reducing the circumference ofthe winding spindle 19, so that the wound up foil 2 can slide off thewinding spindle 19 by itself. Thereby it can be arranged for the woundup foil to fall directly into a funnel 23 and to be compacted in asubsequently arranged roller

We claim:
 1. A method of removing a foil wrapping from a stock of goodscomprising the steps of:a) vertically cutting open the foil wrappingdrawn over the stack of goods on one side of the stack of goods; b)seizing a portion of the foil wrapping which is vertically cut open andfastening said portion to a winding spindle having a verticallongitudinal axis; c) winding the foil wrapping onto the winding spindleby rotating the winding spindle about said longitudinal axis; d)simultaneously guiding said winding spindle around the stack of goods asthe foil is wound on said spindle, thereby removing the foil wrappingfrom said stack of goods.
 2. The method according to claim 1 wherein thefoil wrapping is lifted off the stack of goods area by area and cutopen.
 3. The method according to claim 1 wherein the winding spindle isguided around the stack of goods at a distance therefrom which remainsconstant.
 4. The method according to claim 1 wherein the winding spindlerotating about its longitudinal axis pulls itself on the foil around thestack of goods.
 5. The method according to claim 1 wherein the foilwrapping is at least partially heated, area by area, prior to unwinding.6. The method according to claim 1 wherein the foil wrapping is heatedin the an area underneath the stack of goods.
 7. The method according toclaim 1 wherein the foil wrapping is heated in an area of a palletsupporting the stack of goods.
 8. The method according to claim 1wherein the stack of goods is lifted for removal of foil shrunk on abottom of the stack.
 9. A device for removing of a foil wrapping drawnover a stack of goods, comprising:a frame; a supporting arm supported onsaid frame so that said arm can rotate about a vertical axis and can bedriven about the axis; a winding spindle suspended from said arm andhaving a vertical spindle axis; a guide slide carriage slidable on saidarm, the winding spindle and a guide mast parallel to said spindle beingsuspended from said arm, and a separating element on said mast shiftabletoward said foil wrapping for separating a tab of said foil wrapping forenabling said foil wrapping to be wound up on said spindle as saidspindle is rotated and displaced around said stack.
 10. The deviceaccording to claim 9, wherein the separating element has a suctionmember which can be connected to a suction source.
 11. The deviceaccording to claim 9 wherein the separating element includes a blade.12. The device according to claim 9 wherein the separating elementincludes a heating wire extending parallel to the winding spindle. 13.The device according to claim 9 wherein the guide mast adjustable hotair nozzles are arranged in its longitudinal direction.
 14. The deviceaccording to claim 9 wherein at a lower end of the guide mast a suctionmember is connected to said separating element.
 15. The device accordingto claim 9 wherein the frame is equipped with hold-down means which isprovided with at least one heating wire extending from a center, forproducing tearing lines in an upper side of the foil wrapping.
 16. Thedevice according to claim 9 wherein a heating wire is provided forcutting said foil wrapping and has an antiadhesion coating.
 17. Thedevice according to claim 9 wherein the winding spindle has twoshell-shaped cheeks one of said cheeks being swingable with respect tothe other of said cheeks so that, when a cross section of the windingspindle is a maximum, a foil tab can be clamped between the cheeks and,when the cross section of the winding spindle is minimal, a winding ofthe foil wrapping can be removed.